Author Topic: Thoughts on 1970 340 build..  (Read 1066 times)

Offline challngd73

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Thoughts on 1970 340 build..
« on: May 22, 2014 - 07:48:33 PM »
Ok my 340 is at the machine shop now getting a sleeve.  These are my thoughts for where to go.. It is a 1970 340 bored  .60 over, forged crank.  I am looking at diamond forged pistons 10.5 to 1, airwolf 220 heads, eddy rpm airgap intake, tti headers, 727 tranny, 3.55 suregrip rear, in a 1966 cuda.  I will match converter to cam, once i pick one.  I am leaning towards lunati voodoo flat tappet 268/276, but I  also wonder about a hydraulic roller grind.   What benefits is there to going roller?  Also, Which   lunati roller cam  would  you all recommed?




Offline Chryco Psycho

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Re: Thoughts on 1970 340 build..
« Reply #1 on: May 22, 2014 - 08:34:57 PM »
4 types of cams , hyd flat tappet & roller
 Solid flat tappet & roller
 all have advantages & disadvantages
 Hydraulics can collapse with high spring pressures so the ramps are milder
 flat tappets need high zinc oil nothing off the shelf works
Hyd rollers are great for milder street performance
 Solid rollers can starve for oil but give the best performance .
 I typically use solid flat tappets , best performance & reliability

Challenger - You`ll wish You Hadn`t

Offline challngd73

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Re: Thoughts on 1970 340 build..
« Reply #2 on: May 22, 2014 - 08:42:34 PM »
Do solid flat tappet cams need more adjustments like valve lash and such?  What cam would you recommend for that particular build Chryco? Flat top pistons btw.  I want a nice forged light weight piston.  What brand pistons do you prefer? Car weighs approx 2900 without driver.     I just want her to  be a fast around town cruiser, that isnt too shabby at the track every once in awhile.

Offline Chryco Psycho

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Re: Thoughts on 1970 340 build..
« Reply #3 on: May 22, 2014 - 10:47:03 PM »
Flat tappet solids do not need constant adjustment , think Cummins & slant 6 , I usually set them once / year
I used the TF60 / Tf57 110 cl a lot in street driven cars , good wide powerband without revving excessively

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Offline cudabob496

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Re: Thoughts on 1970 340 build..
« Reply #4 on: May 23, 2014 - 03:56:11 AM »
doesn't roller also mean less valve train friction and therefor a hp gain??
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline crash340

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Re: Thoughts on 1970 340 build..
« Reply #5 on: May 23, 2014 - 07:43:30 AM »
I also though, happy to be corrected the following for roller hydraulics cams
No need for zinc additive
Not as agressive duration meaning better less lumpy idle, more vacum at idle but a quicker taller lift meaning you can have a more streetable engine with good HP gain :dunno:

Im thinking of going hydraulic roller cam on a 408 build with Airwolf heads, 10.5 CR (approx) forged crank, undecided on intake and injection path (direct port/ carb EFI/six pack EFI). my goal is 550hp
Greg

73 Cuda
Brisbane, Australia

Offline cudabob496

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Re: Thoughts on 1970 340 build..
« Reply #6 on: May 24, 2014 - 05:31:10 AM »
I also though, happy to be corrected the following for roller hydraulics cams
No need for zinc additive
Not as agressive duration meaning better less lumpy idle, more vacum at idle but a quicker taller lift meaning you can have a more streetable engine with good HP gain :dunno:

Im thinking of going hydraulic roller cam on a 408 build with Airwolf heads, 10.5 CR (approx) forged crank, undecided on intake and injection path (direct port/ carb EFI/six pack EFI). my goal is 550hp

I have a solid roller, 254/258 at .050. and .625 lift.  Its also very streetable, and should make you the most hp, especially with the airwolf heads. They can handle a lot of airflow.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000